The way absolute paths (those starting with a slash character), when passed to get_dir2() are treated differs per ra backend. ra_local and ra_svn both treat a path that starts with a slash to mean a path relative to the current ra context path. ra_dav treats it as a path relative to the host. Even if passing a path starting with a / to get_dir2() is forbidden, the behaviour should be consistent across backends.
Original issue reported by jrvernooij